HIF prolyl-hydroxylase
HIF prolyl-hydroxylase is an enzyme involved in the HIF signalling pathways, and is the target for a set of therapeutic drugs called HIF prolyl-hydroxylase inhibitors.
Hypoxia-inducible factor is an evolutionarily conserved transcription factor that allows the cell to respond physiologically to low concentrations of oxygen. A class of prolyl hydroxylases which act specifically on HIF has been identified; hydroxylation of HIF allows the protein to be targeted for degradation. HIF prolyl-hydroxylase has been targeted by a variety of inhibitors that aim to treat stroke, kidney disease, ischemia, anemia, and other important diseases. Clinically observed prolyl hydroxylase domain mutations, as in the case of erythrocytosis- and breast cancer-associated PHD2 mutations, affect its selectivity for its HIF substrate, which has important implication for drug design.
In humans, there are three isoforms of hypoxia-inducible factor-proline dioxygenase. These are PHD1, PHD2 and PHD3. PHD2, in particular, was identified as the most important human oxygen sensors due to its slow reaction with oxygen.
